Why aren't line breaks/carriage returns showing in an email template?

Why aren't line breaks/carriage returns showing in an email template?

I've created a couple of email templates and during creation and in the preview the line breaks/spaces show up fine where I've pressed return/enter to create new paragraph.

However, when the email is sent all the spaces are missing. You can tell where I've hit return but it doesn't show space between lines.

Any thoughts?